Non-leptonic heavy-hadron decays and local duality

We discuss local duality for weak non-leptonic B and Λb decays in the mb → ∞ limit under the hypothesis of factorization and in the Shifman-Voloshin limit. We show that, under these hypotheses, local duality holds for the first two terms in the 1mb expansion and at the order αs in the perturbative expansion. The possible relevance of these results for the operator product expansion evaluation of the b-hadron lifetimes is discussed.